Actual source code: ex126f.F

  1: !
  2: ! This program is modified from a user's contribution.
  3: ! It illustrates how to call MUMPS's LU solver
  4: !

  6:       program main
  7: #include <petsc/finclude/petscmat.h>
  8:       use petscmat
  9:       implicit none

 11:       Vec            x,b,u
 12:       Mat            A, fact
 13:       PetscInt       i,j,II,JJ,m
 14:       PetscInt       Istart, Iend
 15:       PetscInt       ione, ifive
 16:       PetscBool      wmumps
 17:       PetscBool      flg
 18:       PetscScalar    one, v
 19:       IS             perm,iperm
 20:       PetscErrorCode ierr
 21:       PetscReal      info(MAT_FACTORINFO_SIZE)

 23:       call PetscInitialize(PETSC_NULL_CHARACTER, ierr)
 24:       if (ierr .ne. 0) then
 25:         print*,'Unable to initialize PETSc'
 26:         stop
 27:       endif
 28:       m    = 10
 29:       one  = 1.0
 30:       ione = 1
 31:       ifive = 5

 33:       wmumps = PETSC_FALSE

 35:       call PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,                   &
 36:      &                        '-m',m,flg, ierr)
 37:       call PetscOptionsGetBool(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,                  &
 38:      &                         '-use_mumps',wmumps,flg,ierr)

 40:       call MatCreate(PETSC_COMM_WORLD, A, ierr)
 41:       call MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m*m, m*m, ierr)
 42:       call MatSetType(A, MATAIJ, ierr)
 43:       call MatSetFromOptions(A, ierr)
 44:       call MatSeqAIJSetPreallocation(A,ifive, PETSC_NULL_INTEGER, ierr)
 45:       call MatMPIAIJSetPreallocation(A,ifive,PETSC_NULL_INTEGER,ifive,  &
 46:      &     PETSC_NULL_INTEGER,ierr)

 48:       call MatGetOwnershipRange(A,Istart,Iend,ierr)

 50:       do 10, II=Istart,Iend - 1
 51:         v = -1.0
 52:         i = II/m
 53:         j = II - i*m
 54:         if (i.gt.0) then
 55:           JJ = II - m
 56:           call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
 57:         endif
 58:         if (i.lt.m-1) then
 59:           JJ = II + m
 60:           call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
 61:         endif
 62:         if (j.gt.0) then
 63:           JJ = II - 1
 64:           call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
 65:         endif
 66:         if (j.lt.m-1) then
 67:           JJ = II + 1
 68:           call MatSetValues(A,ione,II,ione,JJ,v,INSERT_VALUES,ierr)
 69:         endif
 70:         v = 4.0
 71:         call  MatSetValues(A,ione,II,ione,II,v,INSERT_VALUES,ierr)
 72:  10   continue

 74:       call MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY, ierr)
 75:       call MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY, ierr)

 77:       call VecCreate(PETSC_COMM_WORLD, u, ierr)
 78:       call VecSetSizes(u, PETSC_DECIDE, m*m, ierr)
 79:       call VecSetFromOptions(u, ierr)
 80:       call VecDuplicate(u,b,ierr)
 81:       call VecDuplicate(b,x,ierr)
 82:       call VecSet(u, one, ierr)
 83:       call MatMult(A, u, b, ierr)

 85:       call MatFactorInfoInitialize(info,ierr)
 86:       call MatGetOrdering(A,MATORDERINGNATURAL,perm,iperm,ierr)
 87:       if (wmumps) then
 88:           write(*,*) 'use MUMPS LU...'
 89:           call MatGetFactor(A,MATSOLVERMUMPS,MAT_FACTOR_LU,fact,ierr)
 90:       else
 91:          write(*,*) 'use PETSc LU...'
 92:          call MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_LU,fact,ierr)
 93:       endif
 94:       call MatLUFactorSymbolic(fact, A, perm, iperm,                                   &
 95:      &         info, ierr)
 96:       call ISDestroy(perm,ierr)
 97:       call ISDestroy(iperm,ierr)

 99:       call MatLUFactorNumeric(fact, A, info, ierr)
100:       call MatSolve(fact, b, x,ierr)
101:       call MatDestroy(fact, ierr)

103:       call MatDestroy(A, ierr)
104:       call VecDestroy(u, ierr)
105:       call VecDestroy(x, ierr)
106:       call VecDestroy(b, ierr)

108:       call PetscFinalize(ierr)
109:       end

111: !/*TEST
112: !
113: !   test:
114: !
115: !   test:
116: !     suffix: 2
117: !     args: -use_mumps
118: !     requires: mumps
119: !
120: !TEST*/